Title: Clap Switch

I. Summary

A Clap Switch circuit uses a microphone within the circuit to detect noises to

turn the LED on. A clap switch circuit can be used in homes and businesses to turn on

things such as: lights, TVs, or whatever it is set up to the clap switch. In many cases

you can snap your fingers, clap your hands, or even speak to it. In fact, with modern

technology, you can use commands to activate a piece/pieces of technology to allow

it to turn on/off from anywhere within the room of the Clap Switch.

II. Objective

Individuals will construct a Clap Switch circuit and gain based knowledge on

the 555 timer IC, BC547 Transistor and the condenser microphone. Also, individuals

will get to see exactly how you can turn things on by a simply clap, snap, and/or the

use of the voice.

III. Industry

Clap Switches can be installed into businesses and homes to allow individuals

to turn lights and a number of technology on or off by using claps, snaps, or his/her

voice. Clap Switches gives individuals the ability to remain seated or lying down to

turn devices on or off. Also, this device is important to industries because technology

is growing at an extreme rate and with the component within the Clap Switch it can

help advance technology even more. In today’s world, we use voice control within

our mobile devices, as well as, devices like the Echo, Google Home, etc. Within these

devices that I previously listed, you can turn on a number of technologies by giving it

simple voice commands, which is something that a great number of companies are

working on – on a daily basis.

The Clapper was released in the 1980s, allowing individuals to active

appliances by using claps all without having to get up to turn on an appliance

manually. (i) The Clapper was only the beginning of audio activation technology.

Now, there are devices like the Google Home smart speaker – which has similar

functionalities like “The Clapper”, yet it is more advanced. For instance, you can

speak to the speaker and ask it to turn on any smart appliances, play music, and ask it

to do whatever you need it to do. (ii)

IV. Methodology

a. Parts

i. 555 timer IC

ii. Two BC547 Transistor

iii. 3.3 Ω Resistor

iv. 1kΩ Resistor

v. Two 270Ω Resistors

vi. 100nF Capacitor

vii. 22uF Capacitor

viii. Two Light-emitting Diode

ix. Condenser Microphone

x. Breadboard

xi. Digital multimeter

xii. Power Supply

xiii. Wires

b. Purpose of Parts

i. 555 timer IC is used to timing function, such as turning the LED on for a

short period of time.

ii. The BC547 transistor is used for amplification.

iii. Anode/ Collector of the transistor in pin 1.

iv. Base of the transistor is pin 2.

v. Cathode/Emitter of the transistor is pin 3.

vi. The 270 Ω resistor determines the order at the output and the sensitivity.

vii. The 22uF capacitor allows the LED to stay on for approximatively 2.5

seconds.

c. Procedure

i. Connect the power supply and breadboard together to set the voltage to 5

volts.

ii. Connect the ground to the breadboard

iii. Connect one terminal of the 3.3kΩ resistor.

iv. Connect the positive end of the condenser microphone to the voltage

source and place the negative end of the condenser microphone to the

resistor.

v. Connect the base of the BC547 transistor to the condenser microphone.

vi. Connect the emitter of the transistor to the ground.

vii. Connect the resistor to the voltage source and the collector of the

transistor.

viii. Place the second BC547 transistor onto the breadboard.

ix. Connect the collector of the first BC547 transistor to the base of the

second BC547 transistor.

x. Connect the emitter of the second BC547 transistor to the ground.

xi. Place the 555 timer IC onto the breadboard.

xii. Connect pin 6 with pin 7 of the 555 timer IC.

xiii. Connect pin 4 with pin 8 of the 555 timer IC.

xiv. Connect the 100k-ohm resistor to pin 7 and pin 8.

xv. Connect the anode of the 20uF capacitor to pin 6 of the 555 timer IC.

xvi. Connect the cathode of the 20uF capacitor to the ground.

xvii. Connect a LED to pin 3 of the 555-timer.

xviii. Connect a 270-ohm resistor to the cathode of the LED and to the ground.

xix. Connect pin 1 of the 555-timer to the ground.

xx. Connect pin 4 of the 555-timer to the voltage source.

xxi. Connect a 1k-ohm resistor to the anode and the voltage source.

xxii. Connect a 100nF Capacitor to the anode of the second transistor and into

pin 2 of the 555-timer IC.

d. References and Photos

i. https://home.howstuffworks.com/clapper.htm

ii. https://support.google.com/googlenest/answer/9286728?hl=en

iii. https://www.youtube.com/watch?v=DkbfBIMSdgo&t=102s